Identification of Two Long Noncoding RNAs, Kcnq1ot1 and Rmst, as Biomarkers in Chronic Liver Diseases in Mice

Abstract

This study investigates novel short-lived long noncoding RNAs (lncRNAs) in mice with altered expression in metabolic dysfunction-associated steatotic liver (MASH) and liver fibrosis. LncRNAs share similarities with mRNAs in their transcription by RNA polymerase II, possession of a 5' cap structure, and presence of a polyA tail. We identified two lncRNAs, Kcnq1ot1 and Rmst, significantly decreased in both conditions. These lncRNAs showed dramatic expression changes in MASH livers induced by Western diets and CCl₄, and in fibrotic livers induced by CCl₄ alone. The decrease was more pronounced in liver fibrosis, suggesting their potential as biomarkers for disease progression. Our findings are consistent across different fibrosis models, indicating a crucial role for these lncRNAs in MASH and liver fibrosis in mice. With MASH becoming a global health issue and its progression to fibrosis associated with hepatocarcinogenesis and poor prognosis, understanding the underlying mechanisms is critical. This research contributes to elucidating lncRNA functions in murine liver diseases and provides a foundation for developing novel therapeutic strategies targeting lncRNAs in MASH and liver fibrosis, offering new avenues for potential therapeutic interventions.

Keywords: Kcnq1ot1; Rmst; hepatocellular carcinoma; lncRNAs; mouse liver.

Figure 1

Mouse model fed Western diet (WD) and treated by CCl₄-induced metabolic dysfunction-associated steatotic liver, which develops metabolic dysfunction-associated steatohepatitis (MASH). Control mice are fed in a control diet (CD). Hematoxylin and eosin (H&E) staining of livers from (A; left) CD-fed and (B; left) WD-fed mice. Sirius Red staining of livers from (A; right) CD-fed and (B; right) WD-fed mice. Scale bar: 100 μm. Arrowheads: hepatocyte ballooning, Arrows: infiltration of inflammatory cells.

Figure 2

Carbon tetrachloride (CCl₄) induced mouse model, which develops liver fibrosis. Control mice are fed in a control diet (CD) with no administration of CCl₄. Hematoxylin and eosin (H&E) staining of livers from (A; left) control and (B; left) CCl₄ injected mice. Sirius Red staining of livers from (A; right) control and (B; right) CCl₄ injected mice. Scale bar: 100 μm. Arrows: infiltration of inflammatory cells.

Figure 3

Alterations in lncRNA expression levels in model mice. Expression levels of the indicated RNAs were determined by RT-qPCR. GAPDH was used for normalization. Values represent the mean ± SD obtained from two (A) and four (B) independent experiments (** p < 0.01, Student’s t-test). The Y-axis indicated that the expression levels of WD-fed mice were divided by those of CD-fed mice. Thus, zero indicated that the RNA was not detectable and one indicated that there was no change in expression levels compared to the CD-fed mice.